Baseband analog front-end and digital back-end for reconfigurable multi-standard terminals

Multimedia applications are driving wireless network operators to add high-speed data services such as Edge (E-GPRS), WCDMA (UMTS) and WLAN (IEEE 802.11a,b,g) to the existing GSM network. This creates the need for multi-mode cellular handsets that support a wide range of communication standards, each with a different RF frequency, signal bandwidth, modulation scheme etc. This in turn generates several design challenges for the analog and digital building blocks of the physical layer. In addition to the above-mentioned protocols, mobile devices often include Bluetooth, GPS, FM-radio and TV services that can work concurrently with data and voice communication. Multi-mode, multi-band, and multi-standard mobile terminals must satisfy all these different requirements. Sharing and/or switching transceiver building blocks in these handsets is mandatory in order to extend battery life and/or reduce cost. Only adaptive circuits that are able to reconfigure themselves within the handover time can meet the design requirements of a single receiver or transmitter covering all the different standards while ensuring seamless inter-interoperability. This paper presents analog and digital base-band circuits that are able to support GSM (with Edge), WCDMA (UMTS), WLAN and Bluetooth using reconfigurable building blocks. The blocks can trade off power consumption for performance on the fly, depending on the standard to be supported and the required QoS (Quality of Service) leve

Low Power Processor Architectures and Contemporary Techniques for Power Optimization – A Review

The technological evolution has increased the number of transistors for a given die area significantly and increased the switching speed from few MHz to GHz range. Such inversely proportional decline in size and boost in performance consequently demands shrinking of supply voltage and effective power dissipation in chips with millions of transistors. This has triggered substantial amount of research in power reduction techniques into almost every aspect of the chip and particularly the processor cores contained in the chip. This paper presents an overview of techniques for achieving the power efficiency mainly at the processor core level but also visits related domains such as buses and memories. There are various processor parameters and features such as supply voltage, clock frequency, cache and pipelining which can be optimized to reduce the power consumption of the processor. This paper discusses various ways in which these parameters can be optimized. Also, emerging power efficient processor architectures are overviewed and research activities are discussed which should help reader identify how these factors in a processor contribute to power consumption. Some of these concepts have been already established whereas others are still active research areas. © 2009 ACADEMY PUBLISHER

A neural probe with up to 966 electrodes and up to 384 configurable channels in 0.13 μm SOI CMOS

In vivo recording of neural action-potential and local-field-potential signals requires the use of high-resolution penetrating probes. Several international initiatives to better understand the brain are driving technology efforts towards maximizing the number of recording sites while minimizing the neural probe dimensions. We designed and fabricated (0.13-μm SOI Al CMOS) a 384-channel configurable neural probe for large-scale in vivo recording of neural signals. Up to 966 selectable active electrodes were integrated along an implantable shank (70 μm wide, 10 mm long, 20 μm thick), achieving a crosstalk of −64.4 dB. The probe base (5 × 9 mm2) implements dual-band recording and a 1

A low-power reconfigurable logic array based on double-gate transistors

A fine-grained reconfigurable architecture based on double gate technology is proposed and analyzed. The logic function operating on the first gate of a double-gate (DG) transistor is reconfigured by altering the charge on its second gate. Each cell in the array can act as logic or interconnect, or both, contrasting with current field-programmable gate array structures in which logic and interconnect are built and configured separately. Simulation results are presented for a fully depleted SOI DG-MOSFET implementation and contrasted with two other proposals from the literature based on directed self-assembly

Array-based architecture for FET-based, nanoscale electronics

Advances in our basic scientific understanding at the molecular and atomic level place us on the verge of engineering designer structures with key features at the single nanometer scale. This offers us the opportunity to design computing systems at what may be the ultimate limits on device size. At this scale, we are faced with new challenges and a new cost structure which motivates different computing architectures than we found efficient and appropriate in conventional very large scale integration (VLSI). We sketch a basic architecture for nanoscale electronics based on carbon nanotubes, silicon nanowires, and nano-scale FETs. This architecture can provide universal logic functionality with all logic and signal restoration operating at the nanoscale. The key properties of this architecture are its minimalism, defect tolerance, and compatibility with emerging bottom-up nanoscale fabrication techniques. The architecture further supports micro-to-nanoscale interfacing for communication with conventional integrated circuits and bootstrap loading

Seven strategies for tolerating highly defective fabrication

In this article we present an architecture that supports fine-grained sparing and resource matching. The base logic structure is a set of interconnected PLAs. The PLAs and their interconnections consist of large arrays of interchangeable nanowires, which serve as programmable product and sum terms and as programmable interconnect links. Each nanowire can have several defective programmable junctions. We can test nanowires for functionality and use only the subset that provides appropriate conductivity and electrical characteristics. We then perform a matching between nanowire junction programmability and application logic needs to use almost all the nanowires even though most of them have defective junctions. We employ seven high-level strategies to achieve this level of defect tolerance

A scalable multi-core architecture with heterogeneous memory structures for Dynamic Neuromorphic Asynchronous Processors (DYNAPs)

Neuromorphic computing systems comprise networks of neurons that use asynchronous events for both computation and communication. This type of representation offers several advantages in terms of bandwidth and power consumption in neuromorphic electronic systems. However, managing the traffic of asynchronous events in large scale systems is a daunting task, both in terms of circuit complexity and memory requirements. Here we present a novel routing methodology that employs both hierarchical and mesh routing strategies and combines heterogeneous memory structures for minimizing both memory requirements and latency, while maximizing programming flexibility to support a wide range of event-based neural network architectures, through parameter configuration. We validated the proposed scheme in a prototype multi-core neuromorphic processor chip that employs hybrid analog/digital circuits for emulating synapse and neuron dynamics together with asynchronous digital circuits for managing the address-event traffic. We present a theoretical analysis of the proposed connectivity scheme, describe the methods and circuits used to implement such scheme, and characterize the prototype chip. Finally, we demonstrate the use of the neuromorphic processor with a convolutional neural network for the real-time classification of visual symbols being flashed to a dynamic vision sensor (DVS) at high speed.Comment: 17 pages, 14 figure